Classic Computer Magazine Archive Article from Compute! magazine

Joystick TV Interference
I have a VIC, and whenever I plug in my joystick, the TV screen gets all fuzzy. What causes this?
Enrique Sanchez Vivar

Probably the joystick cord is acting as an antenna and broadcasting radio frequency (RF) interference generated by the computer, thereby affecting the TV picture. Try positioning the TV differently and keeping the joystick cord as far away from the set as possible.
    The ground to your computer may be poor as well, causing the ground track to act as an antenna. If your VIC power supply has a three-prong plug, avoid using an adapter to plug it into a two-prong socket. It's also possible that a ground track on the circuit board inside the computer has been broken if the computer was dropped or jolted.
    All computers generate RF interference. If you have an early VIC, it emits more "noise" than recent models. Newer computers generally have more shielding to keep these stray signals from escaping. For more information, a booklet entitled How to Identify and Resolve Radio-TV Interference Problems is available from the Federal Communications Commission. Write to the U.S. Government Printing Office, Washington, D.C. 20402 and ask for Stock No. 004-000-00345-4.